This is an prospective study to evaluate the safety and efficacy of naxitamab monotherapy or combined with chemotherapy or combined with chemotherapy and checkpoint inhibitor in the treatment of pediatric high-risk and refractory/relapsed neuroblastoma in Sun Yat-sen University Cancer Center.

Patients with high risk neuroblastoma who obtain CR after chemotherapy combined with surgery, radiotherapy and/or hematopoietic stem cell transplantation received axitamab and GM-CSF. Patients with high-risk neuroblastoma treated by chemotherapy combined with surgery, radiotherapy and or hematopoietic stem cell transplantation patients with tumor residual or progression during treatment (refractory) received naxitamab and GM-CSF in combination with irinotecan and temozolomide or naxitamab and GM-CSF in combination with irinotecan and temozolomide and PD-1 antibody.

Inclusion Criteria:

1)Confirmed diagnosis of high-risk NB 2)1 year of age or above 3)Patient or parent/guardian must provide written informed consent to participate 4)If patient is sexually active, the patient agrees to use effective contraception 5)Confirmed negative urine pregnancy test for sexually active female of child-bearing potential (post-menarche)

Exclusion Criteria:

1. Significant organ toxicity

2. Known or suspected allergy or hypersensitivity to anti-GD2 antibodies or to GM-CSF or its s components.

3. Patient is pregnant, planning to become pregnant (while being treated with naxitamab) or is currently breastfeeding

4. Patient will undergo treatment with another investigational drug, whilst being treated with naxitamab or has received another investigational drug within the 4 weeks prior to commencing treatment with naxitamab

5. Patient is either eligible and able to participate in or is currently participating in an active interventional Y-mAbs sponsored clinical trial with naxitamab within the indication applied for

6. Patient is unable to comply with the naxitamab treatment or has a medical condition that would potentially increase the severity of the toxicities experienced from naxitamab treatment at the discretion of the treating physician

7. Left ventricular ejection fraction of <50% by echocardiography OR other clinically relevant cardiac disorders at the discretion of the investigator

8. Inadequate pulmonary function defined as evidence of dyspnea at rest, exercise intolerance, and/or chronic oxygen requirement. In addition, room air pulse oximetry < 94% and/or abnormal pulmonary function tests if these assessments are clinically indicated

   Applicable for treatment with naxitamab in combination with GM-CSF only:

9. Patient has active progression of the NB disease

10. Patient has active NB disease at primary site or soft-tissue metastasis

11. Patient has known CNS metastases when initiating naxitamab treatment